The present invention relates to a toner handling apparatus for use in transfer-type electrophotographic copying machines, such as a toner collecting container for accommodating the toner collected from the photoconductive drum by a cleaner, or an image forming unit which comprises a photoconductive drum and a developing device and/or a cleaner provided around the drum as assembled therewith and which is removably installable in the main body of the copying machine.
Electrophotographic copying machines of the transfer type are provided with a cleaner for collecting the residual toner which has not been transferred to copy paper in order to repeatedly use the photoconductive drum. The toner collected by the cleaner contains particles of copy paper, fragments of the material forming the photosensitive layer of the photoconductive drum, etc., while the toner itself sometimes remains charged by the transfer charger to a polarity unsuited to the formation of copy images. If recycled to the developing device for reuse, such collected toner produces smudged copies and is therefore not normally recycled but rather is collected in a container for disposal.
However, when the container is removed to discard the collected toner, toner particles are likely to escape from the container to stain the interior of the copying machine and the hands of the operator.
On the other hand, U.S. Pat. No. 3,985,436 recently proposes an electrophotographic copying machine in which the photoconductive drum, and the developing device, cleaner and other elements arranged around the drum for forming images are assembled into an image forming unit which is removably installed in the machine main body to assure easy maintenance and efficient repairs. With this copying machine, the image forming unit needs only to be replaced during the periodic maintenance and inspection of the elements around the photoconductive drum and for repairs thereof. This greatly reduces the period of time during which the user is unable to use the copying machine and also assures an improved service efficiency because the serviceman has only to collect the removed image forming unit and discard the unit or make the unit ready for reuse in a service factory.
Nevertheless, since toner is accommodated in the developing device and the cleaner constituting the image forming unit, the toner scatters when the unit is removed to stain the interior of the copying machine, the neighborhood thereof, the garment of the operator, etc.
To solve the above problem, Published Examined Japanese Patent Application SHO No. 54-29378 proposes a cleaner which is internally provided with specific heating means for melting the collected toner, but the proposed cleaner has the drawback that the heating means, which is disposed in the vicinity of the photoconductive member, adversely affects the photoconductive member with heat and requires much power consumption.